Fields

What is a Field?

In the Datacake Cloud the measured values of your devices are stored in so-called fields. These are "fields" in our time series database. Depending on your subscription plan, a certain number of fields can be created per device.

Creating a new Field

To create your own field, open any device and navigate to its configuration area using the tab bar.

There you scroll down a little until you see the "Fields" panel:

Just click on the blue button "Add Field" to create a new field. The following dialog should appear:

Name

This is the displayed, readable name as it can be used in the portal, e.g. to give widgets on dashboards a title or in other places.

You can change this name at any time later.

Identifier

The identifier is a unique designation that is used for storing data in the database.

Once the field is created, the identifier cannot be changed. If you still want to change it, you must delete the field.

Types

We support following field-types:

Integer

Stores integers like 1234567.

Float

Stores numbers with decimal places, even floating point, such as 1234.56. This type is suitable for storing values with decimal places, such as

  • Temperature

  • Pressure

  • Air quality

String

Save complete character strings. like Sensor OK, Your own payload information, A83B8CFH38420. These are being stored unprocessed in the database including a timestamp.

Use this data type to store e.g.:

  • status messages

  • events

  • Your own payload data

In addition, strings can be used in conjunction with mapping fields to convert numeric sensor values into a status via look-up table.

Boolean

Via Boolean fields you can store measured values of digital signals that are either only 0 or 1, or True or False. Use these for:

  • Status-Signals of digital Inputs

  • True / False conditions

  • Events

Counter

You can use a counter field to measure the relative change of an absolute value over time.

Every time a measurement is transmitted, we calculate and store the relative change to the previous recorded value.

If the change is negative, i.e. the transferred value is smaller than the previously transferred value, we assume that the counter has re-started counting from 0 and store the transmitted value instead of the relative change.

This ensures that we can display the consumption as a relative change even after resetting an external meter source.

A counter field can only be used to measure positive changes. If you want to measure a negative change, you must first invert the measurement using a mapping field and a negative scaling factor (for example, -1).

Currently, the counter field type only works with integers. A support for floats will follow.

GEO / Location

Unit

Use the input field to define the unit of the measured values that are being recorded into that field. Thanks to a free text field, you can define any units here, whether °C, PPM, Bar, Fahrenheit or cake, biscuits, whatever.

Conversion

You want to convert units into another one? No problem! Use mapping fields for the conversion of your measurement values via scaling, look-up table or linear scaling of a value range. Use Formula Option of a field to do simple mathematical operations.

Formula

Each field has the function of a formula. Here, simple mathematical operations can be used to combine measured values from other fields or to perform special calculations. More on this topic is given in the following section:

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